Public safety communication systems, such as 911 services, police and firefighter systems, use radio dispatch. A constant in radio dispatch systems is the need to position radio sites, consisting of RF receivers and transceivers, according to geographic topography. However, the call takers are located elsewhere. For example, a 911 operator may be located at a PSAP (Public Service Answering Point). The radio sites are traditionally interconnected with a number of point to point leased lines creating a mesh of lines. The communication system is accessed by emergency personnel, such as police, firefighters and paramedics. Typically, dedicated public safety frequencies are used, which are frequently in the 800 MHz FM range. Nomadic call takers are not supported by these traditional systems.
In the aftermath of the event of Sep. 11, 2001, there is a mandate for there to be interoperability between the communication systems of the various emergency services agencies. Traditionally, each agency operates a private network, which is not programmed to access the frequencies of the other agencies. To make the traditional systems interoperable in a traditional manner, parallel lines are needed, as well as dedicated interoperable channels. The mesh of lines therefore gets more complicated.
Furthermore, each PSAP requires a backup. Using the traditional system, each backup requires its own set of leased lines, thus complicating the mesh of lines even further.
Packet based networks are presently used for VoIP (Voice Over Internet Protocol) communications. These VoIP communications traditionally have a central manager that runs the terminals.